So what exactly is punk? It’s a question that probably goes back at least as far as when The Damned released ‘New Rose’, and tends to get easily muddied in issues of purity and pretension. It was addressed again recently through a tongue-in-cheek, classroom-style approach on Declan Synnott’s  Ain’t You on Dublin Digital Radio. While following along with specially prepared Powerpoint slides and track selections from artists as diverse as Special Interest, Rites of Spring, and Dustin the Turkey (!), Mr.Synnott and his class mused on the punk credentials of various topics. And while there were occasional unambiguous declarations (cats:…